1. A. Björkman and B. Person, Svensk. Papaerstidn.,60, 158 (1957).
2. J. M. Pepper, P. E. T. Baylis, and E. Adler, Can. J. Chem.,37, 1241 (1959).
3. F. Brauns, J. Am. Chem. Soc.,31, 2120 (1939).
4. N. N. Shorygina and Kh. R. Niyazov, Izv. Akad. Nauk SSSR, Ser. Khim., No. 6, 1121; No. 11, 2094 (1962).
5. A. F. Semechkina and N. N. Shorygina, Zh. Obshch. Khim.,28, 119 (1958).